Variable-speed power transmitter for sewing machines



Nov, W23. fi,4-73,3

J. 5:, FENCH VARIABLE SPEED POWER TRANSMITTER FOR SEWING MACHINES Filed Dec. 29 1919 4% Sheets-Sheet 1 WITNESSES: M JrZz Nov. 6, 1923. mm w J. S. FlNCH VARIABLE SPEED POWER TRANSMITTER FOR SEWING MACHINES Filed Dec. 29, 1919 .4 Sheets-Sheet 2 L Q 1 i If wwmzssss; L VENTOR ATTORNEY Nov. 6 R923.

J. S. FINCH v VARIABLE SPEED POWER TRANSMITTER FOR SEWING MACHINES Filed Dec. 29 1919 4 Sheets-Sheet 3 WITNESSES! 424m 34 -WM ATTORNEY Nov 6, E923. 31,42-73,3@

J. 5. FINCH v VARIABLE SPEED POWER TRANSMITTER FOR SEWING FMGHINES Filed Dec. 29 1919 4 Sheets-Sheet 4 I J%1 M ATTORNEY Patented New. G, 1923.

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JOHN'S.- FIITCH, 0F BEIDGEPOBT, CONNECTICUT, ASSIGNOR 'TO"THE' SIlXTGER' IvIZ1\TU FACTURING.-CO1VPANY,' 0F ELIZABETH, NE JERSEY, A COBPORATIONOF NEW EERSEY.

VARIABLE-sense rowan Teaser/limes non snwrne MAcHm-ns.

Application filed December 29, 1919. Serial No. 3431010.

To all whom it may concern Beit known that I, JOHN S; Frnorr, a citizen or the United States, residing at Bridgeport, in thecounty of Fairlield and :3 State of Connecticut, have invented certain new and useful Improvements in Variable- Spced Power Transmitters t'or Sewing-hiachines, of which the following is a specification, reference being had therein'to the accompanying drawings.

This invention relates to improvements lhe present invention also aims to improve the manually operated controlling means for this class 01"- power-transmitters.

The present invention'is designed as an improvement over the power-transmitter disclosed in-U. S. patent to D. Noble, No. '1,001,674,datedAugust 29, 1911. In its preferred en'ib'odiment, a U-shaped hanger depends from the'power-table supporting the machine and sustains coaxially ariged driving and driven pulleys, of which the driving pulleys are rotated at relatively low and high speeds. The driven pulley is secured upon an endwise movable shaft suitably journaled in the hanger and yieldingly ur ed in one direction to normally cause driving engagement between the low speed pulley and the driven pulley, the latter of which is suitably connected by a belt with the sewing machine. In order to shittthe driven] pulley out or". engagement with the low speed pulley andinto engagement with the high speed pulley, there is provided a rock-arm carrying a pulley-shifting cam and adapted to be actuated by an operating lever comprising a knee-shift.

The rock-arm is-fulcrumed upon a-crankpin; projecting ecc e ntrically from a rocflrshaft having an operating handle whereby the fulcrum ofthe 'rock -arm may be moved, to shift the driven pulleycarrying shaft lnto an intermediate neutral position be:

tween the two driving pulleys; This m0ve ment of the rock-shaft positions the operating handle into the pathof movement of the knee shift,1ocking the latter against movement. I I This power-transmitter is particularly adapted for use in connection with a sewing machine such as is disclosedior instance in my U. S. Patent No. 1,39%,075, issued ,Octo her 18, 1921, wherein actuationof the kneeshift maintains the sewing ,inachine in operation for an indefiniteperiod, i. e, until.

the release otthe knee-shift whereupon, a

mechanism is brought into action determining the number of stitches formed after the, releaseott the knee-shift; At a predeteii mined time after this mechanism is brought into action a stop-motion deviceopera'tes to stop the machine in a predetermined position. A

By employingthe present power-transmitter in'connection with thesewinginachine, the release of the knee-shift causes he'sewL ing machine to be driven at low speed "at the time of operation of the stop n otion, there I st by greatlyreducing jarring of the "operatmg parts. M f I In the accompanying: drawings, F g. 1 is a View in front elevation and partly 1n section of the present improved power-transmitter for operating a sewing "machine of thejcharacter described Fig.2 is a right end elevation of the same. Fig. 3 is a longi tudinal' sectional view of the power-transmitter. knee-shift and fulcrum-shiftoperating mechanism. Fig. 5 is adetailview substantially on the line 55, of Fig. 4, illustrating the device employed for limiting the movement of thefulcrum-shiftrock shatt." Fig. 6 is a detail view ott'the mechanism brought into action'by the release of the knee-shift and determining the time of operation of the sewing machine after such release, and Fig. 7 a. view in rear elevation of the machine standard and of'a portion of the overhanging arm. v 1

Referring to the drawings," the present invention is employed in connection with a Fig. ,4: is a top plan view-oftl1e bracket-arm .8 adapted to support and guide sewing machine, supported on a power-ta{ ble 1 and comprising a 'vertical standard .2 curving laterally into 'an overhanging the'needle or; needle-carryingbar, presserg bar and the. other operating parts 7 (not 1 shown) in the usual .manner. Journaled in suitable bearings providedin .theoverhanging bracket-arm .is the. main actuating or driving shaft & of the sewing machin ecarryring at itsouterenda fast pulley 5', a loose pulley 6 and ahand-wheel7, A rock-shaft 8Ji's j ournaled' ii suitable bearings provided V I at therear side of the overhanging bracket arm and cari'ies'a crank-arm 9; connected by means-of a rod "10 wlthl one arm of-a two- 'armed rock-lever 11 pivotally supported r jupon the machineframe by means of a 'pin 1 12 and'normally urged tolift the rod 10 by means of'the spring 13." Theother arm of the'l ver 11 18 adapted to be en aged by the flattened upper surface of a collar 14 carried by the upper end of a rod 15 rigidly secured upon an arm'16 projecting laterally from a swinging-frame 17;

The swinging-frame 17 is provided with oppositely disposed spaced "ears, as '18;

pivotally sustainedby brackets as 19 depending from the table 1. Rigidly secured inthe swinging-frame 17 is the horizontal portion of a rod 20 having a depending end upon which is secured-a plate 21 adapted to beengaged the knee of an operator to rock the swinging-frame 17, and thereby sewing machine,

jecting arm 26 ofthe usual swinging frame 27 of a stop-motion device well known in the art. Thisjstop-motion deviceco nprises a plunger 28, carrying, a collar 29 and em braced by a spring 30 interposed between a shoulder formed on the swinging frame and the collar 29, Secured upon the shaft 4' adjacentthe fast pulley 5 is a cam 3i formed with a stop-notohSQ adapted to be engaged by the end of theplunger 28 in the stopping position ofthe machine. A r arm 38 of the swinging-frame 27 carries a stud 34;

' adapted to be engaged by thel notch 35 of a latch-lever 36 pivotally supported bya fulcrum-pin 37. upon, the fram of the machine, Also carried by the pin 37 is a trip-finger adapted to heengaged by a flange 39 formed on the end of a sleeve 40 splined to the shaft 4 so as to rotatetherewithbut slida-ble longitudinally thereon. The sleeve" 40 is'provided withaworm 41 adapted to be engaged by a nut-4L2 secured by means of about the shaft a screw t3upon an arm 44; suitably clamped ,t 7

upon a shaft l5. The shaft 45 is ournaled in'a suitable bracket provided on the rear sideof the overhanging arm 3 and issurrounded, by colled'fsprlng' 46 acting to 'n'iaintain an arm'f carried by theshaft in contact witha cam/l8 suitablyfsecured. upon the rock-shaft 8. r r

VVhen the plate 21 is shifted to theright asviewed Fig. 1 the rod' 10 is moved downwardly a prev ously descr bed thereby rocking the shaft Sand throughthe link 24L swinging the frame 27 thereby causing the plunger 28 to, be moved laterallyout of'the stop-notch 32-aga1nst the action of a spr ng 49-. The rocking of the shaftSat the same time causes the arm i7 to ride the surface 1 18 of the l ,'thereby lifting the nut 412 out of engagement with the worm'dl. This permits a spring 50 interposed between a collar 50 secured upon the shaft 4: and the sleeve d0 to shift the latter to the right.

lhis movement of theicollar 4E0. releases the finger from the-flangeBQ and permitsthe latch-lever 36 to engage the studle to, hold the swinging-frame 27 out of stopping position. maintainedfor an indefinite pe*iod,' or in other words, so long as the knee-shift is engaged by the operator. W hen the plate 21 is released by the operator a spring 51 coiled 8 causes a rocking movement of the latte in an opposite direction; Thismovement of the rock-shaft 8 permits the arm 4:? to rideoif the surface 18 of the cam .48 and under the action of the spring 46 causes the nutlQ' to engage the rotating against endwise inovemenu-the sleeve 10 is caused to'rnove to the left as indicated in finger-68. "Theswinging frame 2? is now free to be actuated by the spring 49 whereupon the end of the plunger 28 rides the This position ofthe parts may be worm ll; Inasmuch as the nut. 4:2 is held.

'Fig".- 1, thereby tripping the latch-lever 36 under the action of the flange '39 upon the outer periphery oft-he cam 31 until it enters the notch 82 to stop the niachine in a pre-zy determined position. It will be observed,

however, that between the time that the nut 12 is caused to engage the worm 41 and the time of stopping of the maehineseveral stitches willfbe formed andit is during that timethat the machine is driven by the low speed pulley of the power=transinitter about to he described.

V The power-transmitter comprises a substantially iii-shaped hanger 52', suitably secured to the under side of thetable 1 and 5 provided with bossesb and affording bearing-support for th e transmitting. inechanism. Secured in the boss 54: .by'meansof a screw-bolt 55 is a bearlng 56 closed at'its outer end by a cap 57 suitably secured thereto. Secured withinthe bearing 56 by means 60 and at its opposite end against a thrustbearing comprising a ring 63 held in position by mean of a split-ring 64 and in contact with a plurality of balls, as 65, within an annular portion of aring 66. The ring 66 is positioned in an annular recess 67 formed in the bearing 56. Journaled for endwise movement within the bushing 59 is a power-transmitting shaft 68 engaged at one end by the conical end of a pintle 69 of which the outer end projects through an aperture in the cap 57. A coil-spring 70, interposed between the cap 57 and a shoulder on the pint-le 69, acts to normally force the shaft 68 endwise in the bushing 59 and to the left as viewed in Fig. 3. I

Secured upon the shaft 68 by means of the screw 71 is the hub of a driven pulley 72 provided on opposite faces with friction rings 73 and 7 1. On the side of the driven pulley 72 opposite to that of the high speed pulley 62 is a low speed pulley 7 5, the hub 76 of which is journaled upon a bushing 77 secured by a screw 78 within a bearing 79 secured within the boss 53 by means of a screw-bolt 80. The end thrust of the pulley 75 is taken up in the same manner as that described in connection with pulley 62 and need not therefore be further detailed. The driven pulley 72 in the stopping position of the sewing machine is connected by means of a belt 81 with the loose pulley 6. This belt 81 is adapted to be shifted by means of a fork 82, carried by the swinging frame 27, upon the fast-pulley 5 to start the operation of the sewing machine, The driving pulleys 62 and 75 are respectively connected by means of belts 83 and 8 with pulleys 85 and 86 carried by the powcr-shaft 87. It will be observed that the pulley 85 is considerably larger than the pulley 86 thereby rotating the pulley 62 at a considerably higher speec than that of the pulley 75. The friction ring 73 carried by the pulley 72 is adapted to engage the face 88 of the pulley 75 and the friction-ring 7 1 is adapted to engage the face 89 of the pulley 62, these engagements occurring alternately when the shaft 68 is shifted endwise.

On its end opposite to that engaged. by the pintle 69, the shaft 68 is engagedby the conical end of a pintle 90 formed with a slotted outer end affording a wall 91 engaged by a pulley-shifting cam 92 of a rock-arm 93. The hub 94 of the rock-arm 93 is journaled upon the shank 95 of a crank-pin comprising a shouldered screw 96 threaded eceentrically' into the end of a rock-shaft 97. The rock-shaft 97 is journaled in a bracket 98 projecting laterally from a support 99 adjustably secured by means of a SCI'eW-bOlL 100 Within a boss 101 formed on the hanger 52. The rock-shaft 97 is limited in its movements by a pin 102 projecting from the bracket 98 and adapted to be engaged by shoulders provided on diametrically opposite sides of a stop-element 103 preferably integral with the shaft 97. At its outer end there is suitably secured upon the rock-shaft 97 an operating crank 10% having a handle 105. It is evident that the shaft 97 may be turned substantially180 by means of the crank 104. The crank-pin 96 in the positionsillustrated in the several figures of the drawings is by this movement displaced laterally to cause thelcam 92 of the rock-arm 93 to engage the pintle 90 and shift the shaft 68 endwise against the action of the spring 70 to position the driven pulley 72 intermediate the driving pulleys 62 and and in disengaged relation with both of them. Consequently the crank-pin 96 forms a movable fulcrum for the rock-lever 93 and it is evident that by turning the rock-shaft 97 in the opposite direction, the spring 70 may perform its normal. function of maintaining the driven pulley 72 in engagement with the low speed pulley 75. I

In order to shift the driven pulley into engagement with the high speed pulley 62, the rock-arm 93 is provided with a fork 106 bridged by a pin 107 rotatably supported thereby. The pin 107 is provided with a transverse aperture entered by a rod 108 carrying collars, as 109, upon opposite sides of the fork 106. The rod 108 is threaded into a boss 110 of a collar suitably secured upon the rod 20. i

From the foregoing description, it will be seen that movement of the swinging frame 17 to the right as viewed in Fig. 1 not only causes a shifting of the belt 81 from the loose pulley 6 to the fast pulley 5, a release of the stop-motion plunger 28 and a disengagement of the nut 12, hut-also causes a shifting of the driven pulley 72 into driving engagement with the pulley 62 to rotate the machine at high speed through the consequent rocking of the lever 93 upon its fulcrum to cause engagement of the cam 92 with the pint-1e 909 Then the knee-shift is released by the operatgr, the driven pulley 72 is immediately returned into engagement with the low speed pulley 7 5, but inasmuch as the sewing machine is operated for an appreciable interval following the release of the knee-shift as previously described it is evident that the speed of the machine will correspond to the speed of the pulley 75 at the time the plunger 28 engages the notch 32 to stop the machine. Should it be desired v to maintain the driven pulley in neutral'position, the crank 10 1 is turned into the position indicated in the several figures of the drawings to shift the driven pulley in the manner previously described. However, this movement of the crank i placed it into.v the path of movement of the depending portion of the rod thereby locking the knee 7 p The primary advantage derived from the looking I of the shift 21 against movement.

5 knee-shift .while the driven pulleyis in neu tral'position is to prevent an operator from starting the machine while the driven pulley is in this position. 3 Without the provision of the locking device it would be possibleto start the machine from neutralposition and i I stop the samewithout first slowing the speed 7 automatic means at any point 'in the operby contact with the low speed pulley; v-

4 Having thus set torth'the nature-of the; invention, what I claim herein is 1'.- Tlie V combination .with a sewing machine including a stop-motion ,device, automatic; means for initiating a machine arresting action of said stop-motion device, and a inanuallycontrolled device fordetermining thetinie of effective action of said ation of the machine, ofa power-transmitter including a power-transmitting driven pulley, driving connections between said pulley and said sewing machine, relatively connections with said manually controlled low and high speed driving pulleys adapted to be alternately placed in operative engage-i ment with saidvdriven pulley, and operative device for relatively shitting said driving and driven pulleys to drive the sewing machine from said. high speed pulleyduring theiperiodof ineffectiveness of said auto 1 matic means and from said low speed pulley during the time that said automatic means is efiective. I a

2. In a power-transmitter, the coinbina tionwith-a supporting framework, a driven pulley, and relatively low and high speed driving pulleys mounted coaxially with said 'driven pulley, of manually controlled means for relatively shifting the driving and driven pulleys into and out. of driving relationship includinga rocking arm, a pulley shifting cam carried by said rock-arnn an endwise movable'shaft carrying said flIlVtJl pulley, and a movable fulcrum for the rock ing arm.

3. In a power-transmitter, the combina tion with a supporting frameworlna driven pulley, and-relatively low and highspeed driving pulleys mounted coaxially with said driven pulley, of manually controlled means for relatively shifting the driving and driven pulleys torotate the latter at con 7 respondingly low and'high speeds including a rock-arm, an endwise movable shaft,

a movable fulcrum for said roclcar'm, and

means for shifting the'fulcrum of thefrockarm to disengage the driven pulley from both of said driving pulleys.

shifting means inoperative; o e V 7. A power transmitter, in combination '4; In a power-transmitter, the combinationiwith a supportingframework, a driven pulley,jand relatively low and high speed driving I pulleys mounted coaxially with said 'driven, pulley, ofmanually controlledmeans' for relatively shifting [the driving; and

driven pulleys-to rotate'the latter at cor respondingly low and high speeds including a rock-arm, an endwise movable shaft,

.an operating lever for said rockarm, a movable fulcrum for said rook-arm, a 'ful- V crum-shifting lever for said rock-arm adapted to be swung into'the path of moveinent of said operating lever whereby the drivenpulley is disengagedirom both of said driving pulleys and said "operating,

lever is locked against pulley-shifting movemee r r 5. In a power-transmitter, the combina tion with a supporting/framework, a driven pulley, and relatively low and high speed driving pulleys mounted coaxially with said driven pulley, of an endwise movable shaft, 7 a rock-arm, a rock-shaft, a crank-pin carried by said rock-shaft affording a fulcrum for the rock arin, an operating-lever 'ir'or' manually actuating the rockarmto rela-V tively shift the driving and driven pulleys with said sewing machine, relatively low 1 and high speed driving pulleys, means for V relatively shitting said driving and driven pulleys to; drive the latter at correspondingly low and high speeds, and means for I relatively shifting saidldrivingl andidriven pulleys to maintain the driven pulley in'idle position, and render said: first mentioned with a. machine adapted to'be automatically stopped in a predetermined position, a power transmitting, drivenpulley opetratively connected with said machine, driving 7 i opposite sides of said driven pulley, means for relatively shifting the driving and driven pulleys into and out of driving engagement, and means for at will render ing said shifting means inoperative.

In testimony whereoflIhave signed my name to this specification;

r c JOHN s; FINOH.

. pulleys mounted coaxially with and upon 

